Another style or type of GUI is the Dosshell that is included with the MS-DOS 5.0 and MS-DOS 6.2 install version.
Shown below is a screen capture of the Dosshell GUI and the 6 files that are required.
The default screen is divided into two windows with a directory tree (a list of files) in the top window and a list of programs available through the Shell in a lower window.
DosShell was basically a file manager (and a crappy one at that) that would also allow you to execute programs from it and when the program closed you came back to dosshell.
I used to use a menuing system called HDM (Hard Disk Menu) that blew DosShell away, and then after HDM came out I think another one called "ArcMenu" came out which was also very good and maybe a little easier to add apps.
And here I was under the impression that they had come up with dosshell on their own.